Damage of bond in reinforced concrete: A detailed finite element analysis

Numerical simulation of the bond is a powerful and versatile tool to analyze different aspects of reinforcement and concrete interaction, such as the formation of internal cracks, damage of concrete around the bar or bond degradation near the cracks. In the present study, a three-dimensional rib-scale finite element modeling technique was employed to study the latter phenomena. Numerical models were calibrated using the experimentally measured reinforcement strain profiles in the short tensile reinforced concrete elements reported herein and elsewhere. The selected experimental programs cover a wide range of bar diameters (10-29 mm) that are commonly used in the engineering practice. A parametric analysis was performed to identify the key parameters affecting the bond stress distribution in the vicinity of cracks. Based on the results of the parametric analysis, a simple bond damage model was proposed. Unlike the existing models, which take into account a single parameter, namely, bar diameter, the proposed bond damage model also considers the effect of concrete grade and reinforcement strain in the cracked section.